A preferred starting point is an existing building, such as an apartment building, an office building, an administration building or the like, in which access to specific floors is possible only via a stairwell. This also includes situations in which, for example, a modern or already modernized part of a building already comprises at least one elevator system, and an older or non-modernized part of the building is to be equipped with an elevator system. When the building having at least one or at least one additional elevator system is upgraded, accessibility via a staircase in close proximity to the constructed elevator should still be ensured at the same time. In this case, the individual floors of the building should be developed such that they can be reached in a flush and preferably barrier-free manner via the elevator system to be constructed.
One particular application relates to a building of this kind, in which the individual floors can so far be reached only via the existing staircase. This is because conversion, in particular when the staircase is demolished in part, can lead to restrictions to the accessibility of the building, which considerably restricts the scope of application if the usability of the building cannot be ensured during conversion.
DE 10 2011 115 217 A1 discloses a method for converting a double-run stairwell without an elevator shaft into a staircase having a single-run staircase, bridge and elevator shaft in front thereof. In this method, an extension is constructed outside the previous building, which extension comprises an elevator shaft and an expansion of the previous stairwell, which expansion is open towards the previous stairwell. Due to this expansion, landings can be implemented, via which an elevator arranged in the elevator shaft can be accessed. Furthermore, a flight of stairs can be extended into the expansion. As a result, the other flight of stairs in each case can be removed and bridges for the individual levels can be inserted at the points thereof.
The method known from DE 10 2011 115 217 A1 has the disadvantage that implementation may not be possible in each specific case, which therefore restricts the scope of application. A problem in this regard is in particular the large enclosed construction volume of the extension, which is required for expanding the stairwell and for the elevator shaft outside the previous building. This can be problematic with regard to the practically available space and for aesthetic reasons. However, legal regulations should also be observed, which preclude a solution of this kind in principle or at least in practice. For example, regulations with regard to distance spaces to be observed can have the result that the construction project cannot be approved for legal reasons. Alternatively, this can be achieved only with an elevator shaft that is smaller than desired. In addition, facilitations or exemptions with regard to building regulations may not be possible. For example, an exemption of this kind, which relates to facilitations with regard to the required distance spaces, for example, may relate only to retrospectively constructed stairwells, but not to extensive constructions that include an elevator shaft. There is another disadvantage with regard to connecting or directly spatially expanding the stairwell in the additional extension. This may make it necessary to completely integrate the extension into the outer insulation of the building.
DE 10 2014 114 904 A1 discloses arranging an elevator in the stairwell of an existing building. The starting point of the conversion for this known structure is a building that includes a stairwell extending from a basement over several floors and having intermediate landings arranged halfway up each floor. Before conversion, there is the problem that one flight of stairs has to be climbed from each intermediate landing in order to reach a floor. An elevator arranged outside the building, which elevator stops at the intermediate landings, can therefore not allow barrier-free access to the individual floors. It is therefore proposed to attach an extension that expands the stairwell beyond the previous outer wall, the previous intermediate landings, which are arranged inside the original stairwell, becoming components of the new staircase. The removal of a flight of stairs made possible thereby therefore creates space for an elevator arranged inside the previous stairwell.
The structure known from DE 10 2014 114 904 A1 has the disadvantage that opening the previous stairwell to the outside during conversion may make it necessary to completely integrate the extension into the outer insulation. Furthermore, the horizontal cross section provided for constructing the elevator shaft is restricted by the remaining intermediate landings and the available flights of stairs. Therefore, despite extensive conversion measures, only a small elevator can be implemented if necessary.